1. Field of the Invention
The present invention is directed to the design and structure of data terminal or the like which are easily serviced when needed.
2. Description of Related Art
In most instances data terminals such as point of sale terminals include a number of components which are stacked or assembled and inter connected at the point of use. When service is required it is desirable to have access to replaceable units within the covers without disrupting the interconnected components. One technique for accomplishing this result is to provide front access to the replaceable units.
U.S. Pat. Nos. 3,264,601 and 4,682,833 illustrate different structures which allow insertion and removal of modular components arranged in drawer like structures from one side (front) of a cabinet which contains a number of cells or tunnels for receiving the drawers. The drawers, when inserted, engage connectors in each cell or tunnel which are interconnected to form a complete machine.
In a point of sale terminal application it is essential to utilize standard commercially available components wherever possible to control and or reduce cost. In addition, the point of sale terminal application imposes severe operating conditions, especially so when vibration is considered. Each time a sale is completed the cash drawer is opened automatically by the system and closed by the sales clerk. Testing and past experience have established that the cash drawer function involves significant vibrational forces which are transferred to the electrical components within the cabinet.
Since the drawer obscures the view of the connector when inserted in the tunnel it is necessary to align the drawer and the connector in both the horizontal and vertical directions. This can be accomplished with locating pins and mating holes in the components to be aligned. However, in addition it is necessary to provide the proper degree of insertion and a locking mechanism to maintain proper electrical contact in the presence of excessive vibration.